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|1. (WO2018181232) PRODUCTION METHOD FOR RESISTANCE SPOT WELDED JOINT|
|Applicants:||JFE STEEL CORPORATION
|Title:||PRODUCTION METHOD FOR RESISTANCE SPOT WELDED JOINT|
Provided is a production method for a resistance spot welded joint that comprises a three-layer stack of two steel sheets and one aluminum sheet. The method makes it possible to produce a resistance spot welded joint that has favorable joint strength, regardless of the components and combination of steel sheets and aluminum sheets. The method involves stacking two steel sheets and one aluminum sheet such that one of the outermost sheets is a steel sheet and the other is the aluminum sheet and then joining the set of sheets by resistance spot welding. The method includes: a first electrification step that is for applying current to form, between the two steel sheets, a nugget that, when the sheet thickness of the thinner of the two steel sheets is tFe (mm), has a diameter of at least 2√tFe (mm); an electrification suspension step that is for suspending electrification after the first electrification step; and a second electrification step that is for applying current after the electrification suspension step.